If two or more enemies are adjacent to you, you are considered flanked.

I do this because I want to break up the conga line of death that seems to happen every time I run an encounter. What are some of the positives and negatives of going this route?

EDIT: My current party is made up of a dwarf shaman, a shardmind artificer, a dwarf battlemind and a half-orc monk. None of these classes really use flanking for anything special outside of the +2 to attack. Also, the line tends to form toward the end of combat when the combatants are fewer in number than the party. The party doesn't see much need to move; they all have flanking, and the monsters CAN'T move because if they do, they will end up dying or healing one of the people in the line due to the shaman's ability.

3 Answers
3

Wizards has pretty carefully balanced combat advantage and flanking and it might be inadvisable to change it. Let's look at some reasons why.

This makes the rogue incredibly overpowered. Instead of having to use an at-will power like Clever Strike to get CA when she is around an enemy with an ally, she now has the freedom (with no expenditure of action) to move to any spot around an enemy and have CA. This means that she has basically no positioning requirements to gain CA.

Defender's forced movement effects are less useful. If you have a defender who likes to have multiple enemies around him (warden and fighter are two), they might actively try to deter flanking by preventing shifting, slowing enemies or proning enemies. This kind of tactical positioning is taken away if flaking can be achieved by any kind of adjacency.

One creature can flank several other creatures and still maintain a solid tactical position. Consider the following case on a 5x5 grid. Instead of flaking one monster(m), the PCs (P) are now flanking 3 monsters. Allowing a close burst power to have CA on all of them.

See how the flank becomes slight OP here:

xxPxx
xmmmx
xxPxx
xxxxx
xxxxx

The postives are clear. CA is much much easier to get for both sides. You're rogue will love you, you're controller will be indifferent and your defender will probably be ambivalent (he's gonna get hit more, but also dish out more hits). If you use a lot of skirmishers which have powers that do big damage on CA then this migth quickly become a problem for your PCs.

Ultimately the question here is what problem are you trying to solve? I assume your fights must look something like:

xxmxx
xxPxx
xxmxx
xxPxx
xxmxx

For you to be seriously considering this. But this kind of tactical positioning is sub par for everyone. It makes it hard for leaders to heal unless they are in the thick of things. It makes it hard for controllers to target groups with at-wills because they are often party unfriendly, and it makes it hard for strikers and defenders to control the battle field because the striker is getting banged on with no real recourse here (from the monster that's not adjacent to the defender).

Ultimately I'm not sure it's worth changing flanking, but instead choose monsters that can get out of these subpar tactical positions and change the battlefield. Maybe a controller that slides allies to avoid getting attacked by the defender, or more skirmishers who can take huge advantage of the flanks your PCs are giving you.

If your PCs use the same tactics every fight, change the game on them. Monsters in the area have to be watching and know that if they get into the same tactical positions as their predecessors they will end up just as dead.

If you want to shake up players, you might want to find more explicit movement-related solutions. Forced movement is an obvious one: put some monsters with Pull powers to yank players out of the line, or an enemy controller with an Area Burst 1 or 2 with Slide to scramble things around.

A more creative solution might be to come up with monsters that afflict players with effects that make them move around. For example, an artillery monster that afflicts ongoing 5 fire (save ends) to the target and each creature adjacent to it. Now the players will want to make sure they're not adjacent to that character, but that character has an interesting tactical effect he can apply to enemies.

In general though, find specific solutions for specific problems.

If the problem is a common formation, address that formation directly rather than changing mechanics that could have unforeseen consequences in other areas of the game.